PHYNANO > Quantum Transport >
Transport in Non-Conventional Two Dimensional Electron Gases
Transport in non-conventional 2D electron gases encompasses investigations of 2D hole gases or 2D electron gases (2DEGs) in AlAs quantum wells, where the band degeneracies, anisotropic masses, and spin-orbit interactions can lead to novel physics. Currently, our main effort here are on 2 DEGs in membrane structures.
2DEGs on suspended membranes are attractive both for thermodynamic measurements, due to the thermal isolation from the substrate, and for the development of nanoelectromechanical systems (NEMS). We are investigating 2DEGs on suspended membranes based on III-V (AlGaAs/GaAs) heterostructures grown by molecular beam epitaxy (MBE). As verified by quantum Hall-effect (QHE) measurements, the suspended 2DEGs have mobilities and densities comparable to the case of the non-suspended ones. In addition, the resonant modes of the membranes have been measured by means of Michelson interferometry and compared with simulations, and provide supplemental evidence for the full suspension of the membranes. Given the overall good control of the fabrication process, the flexibility of MBE grown heterostructures, and the good quality of the above suspended 2DEGs, new paths open up for thermodynamic measurements and in the field of NEMS, such as the quantum behavior of mesoscopic mechanical systems, motion sensors in the nanoscale and terahertz detectors and sources.
Contacts: Ulf Gennser
And also... Dominique Mailly